1. Field of the Invention
The present invention relates generally to the field of integrated circuits. More particularly, the invention relates to a fast and efficient system and method for selecting a single internal clock signal from multiple internal clock signals to synchronize with an external clock signal.
2. Description of the Related Art
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
In modern systems clock signals are used to coordinate the various operations across circuits, devices and integrated circuits. Due to a variety of reasons, however, a single clock signal is typically inadequate to accommodate all the devices in complex circuits and computer systems. For example, a particular device may operate at a different frequency than a processor, thus necessitating multiple clock signals with multiple frequencies. Additionally, there may be issues associated with jitter performance and skewing of the clock signal when it is distributed at speeds approaching the several-gigahertz-range. One common method for minimizing some of the problems associated with distributing a clock signal at high speeds and achieving various frequencies is locally dividing an external clock and then reproducing or regenerating the clock signal. Once a new clock signal is generated locally it is synchronized with the original clock signal so that the operations of the local device can be coordinated with the rest of the system. The procedure of synchronization of the internal clock may take a relatively large amount of time considering the speeds of today's devices and may bottle-neck the system. Therefore there exists a need to more efficiently synchronize a local clock signal with an external clock signal.
Embodiments of the present invention may address one of more of the problems discussed above.